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Zhao M, Wang N, Jiang X, Ma X, Ma H, He G, Du K, Ma L, Huang T. An integrative data-driven model simulating C. elegans brain, body and environment interactions. NATURE COMPUTATIONAL SCIENCE 2024; 4:978-990. [PMID: 39681671 DOI: 10.1038/s43588-024-00738-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 11/05/2024] [Indexed: 12/18/2024]
Abstract
The behavior of an organism is influenced by the complex interplay between its brain, body and environment. Existing data-driven models focus on either the brain or the body-environment. Here we present BAAIWorm, an integrative data-driven model of Caenorhabditis elegans, which consists of two submodels: the brain model and the body-environment model. The brain model was built by multicompartment models with realistic morphology, connectome and neural population dynamics based on experimental data. Simultaneously, the body-environment model used a lifelike body and a three-dimensional physical environment. Through the closed-loop interaction between the two submodels, BAAIWorm reproduced the realistic zigzag movement toward attractors observed in C. elegans. Leveraging this model, we investigated the impact of neural system structure on both neural activities and behaviors. Consequently, BAAIWorm can enhance our understanding of how the brain controls the body to interact with its surrounding environment.
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Affiliation(s)
- Mengdi Zhao
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Ning Wang
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Xinrui Jiang
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Xiaoyang Ma
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Haixin Ma
- Beijing Academy of Artificial Intelligence, Beijing, China
| | - Gan He
- Beijing Academy of Artificial Intelligence, Beijing, China
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China
| | - Kai Du
- Beijing Academy of Artificial Intelligence, Beijing, China
- Institute for Artificial Intelligence, Peking University, Beijing, China
| | - Lei Ma
- Beijing Academy of Artificial Intelligence, Beijing, China.
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China.
- Institute for Artificial Intelligence, Peking University, Beijing, China.
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, China.
| | - Tiejun Huang
- Beijing Academy of Artificial Intelligence, Beijing, China
- National Key Laboratory for Multimedia Information Processing, School of Computer Science, Peking University, Beijing, China
- Institute for Artificial Intelligence, Peking University, Beijing, China
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2
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Philbrook A, O’Donnell MP, Grunenkovaite L, Sengupta P. Cilia structure and intraflagellar transport differentially regulate sensory response dynamics within and between C. elegans chemosensory neurons. PLoS Biol 2024; 22:e3002892. [PMID: 39591402 PMCID: PMC11593760 DOI: 10.1371/journal.pbio.3002892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 10/10/2024] [Indexed: 11/28/2024] Open
Abstract
Sensory neurons contain morphologically diverse primary cilia that are built by intraflagellar transport (IFT) and house sensory signaling molecules. Since both ciliary structural and signaling proteins are trafficked via IFT, it has been challenging to decouple the contributions of IFT and cilia structure to neuronal responses. By acutely inhibiting IFT without altering cilia structure and vice versa, here we describe the differential roles of ciliary trafficking and sensory ending morphology in shaping chemosensory responses in Caenorhabditis elegans. We show that a minimum cilium length but not continuous IFT is necessary for a subset of responses in the ASH nociceptive neurons. In contrast, neither cilia nor continuous IFT are necessary for odorant responses in the AWA olfactory neurons. Instead, continuous IFT differentially modulates response dynamics in AWA. Upon acute inhibition of IFT, cilia-destined odorant receptors are shunted to ectopic branches emanating from the AWA cilia base. Spatial segregation of receptors in these branches from a cilia-restricted regulatory kinase results in odorant desensitization defects, highlighting the importance of precise organization of signaling molecules at sensory endings in regulating response dynamics. We also find that adaptation of AWA responses upon repeated exposure to an odorant is mediated by IFT-driven removal of its cognate receptor, whereas adaptation to a second odorant is regulated via IFT-independent mechanisms. Our results reveal unexpected complexity in the contribution of IFT and cilia organization to the regulation of responses even within a single chemosensory neuron type and establish a critical role for these processes in the precise modulation of olfactory behaviors.
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Affiliation(s)
- Alison Philbrook
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael P. O’Donnell
- Department of Molecular, Cellular, and Developmental Biology, Yale University, Connecticut, United States of America
| | - Laura Grunenkovaite
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, Massachusetts, United States of America
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3
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Liu J, Bonnard E, Scholz M. Adapting and optimizing GCaMP8f for use in Caenorhabditis elegans. Genetics 2024; 228:iyae125. [PMID: 39074213 PMCID: PMC11457936 DOI: 10.1093/genetics/iyae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/17/2024] [Accepted: 07/17/2024] [Indexed: 07/31/2024] Open
Abstract
Improved genetically encoded calcium indicators (GECIs) are essential for capturing intracellular dynamics of both muscle and neurons. A novel set of GECIs with ultrafast kinetics and high sensitivity was recently reported by Zhang et al. (2023). While these indicators, called jGCaMP8, were demonstrated to work in Drosophila and mice, data for Caenorhabditis elegans were not reported. Here, we present an optimized construct for C. elegans and use this to generate several strains expressing GCaMP8f (fast variant of the indicator). Utilizing the myo-2 promoter, we compare pharyngeal muscle activity measured with GCaMP7f and GCaMP8f and find that GCaMP8f is brighter upon binding to calcium, shows faster kinetics, and is not disruptive to the intrinsic contraction dynamics of the pharynx. Additionally, we validate its application for detecting neuronal activity in touch receptor neurons which reveals robust calcium transients even at small stimulus amplitudes. As such, we establish GCaMP8f as a potent tool for C. elegans research which is capable of extracting fast calcium dynamics at very low magnifications across multiple cell types.
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Affiliation(s)
- Jun Liu
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
| | - Elsa Bonnard
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
- International Max Planck Research School for Brain and Behavior, Bonn 53175, Germany
| | - Monika Scholz
- Max Planck Research Group Neural Information Flow, Max Planck Institute for Neurobiology of Behavior-caesar, Bonn 53175, Germany
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4
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Xue W, Lei Z, Liu B, Guo H, Yan W, Jin YN, Yu YV. Olfactory dysfunction as an early pathogenic indicator in C. elegans models of Alzheimer's and polyglutamine diseases. Front Aging Neurosci 2024; 16:1462238. [PMID: 39411283 PMCID: PMC11473296 DOI: 10.3389/fnagi.2024.1462238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Accepted: 09/16/2024] [Indexed: 10/19/2024] Open
Abstract
Neurodegenerative diseases such as Alzheimer's disease and polyglutamine diseases are characterized by abnormal accumulation of misfolded proteins, leading to neuronal dysfunction and subsequent neuron death. However, there is a lack of studies that integrate molecular, morphological, and functional analyses in neurodegenerative models to fully characterize these time-dependent processes. In this study, we used C. elegans models expressing Aβ1-42 and polyglutamine to investigate early neuronal pathogenic features in olfactory neurons. Both models demonstrated significant reductions in odor sensitivity in AWB and AWC chemosensory neurons as early as day 1 of adulthood, while AWA chemosensory neurons showed no such decline, suggesting cell-type-specific early neuronal dysfunction. At the molecular level, Aβ1-42 or Q40 expression caused age-dependent protein aggregation and morphological changes in neurons. By day 6, both models displayed prominent protein aggregates in neuronal cell bodies and neurites. Notably, AWB neurons in both models showed significantly shortened cilia and increased instances of enlarged cilia as early as day 1 of adulthood. Furthermore, AWC neurons expressing Aβ1-42 displayed calcium signaling defects, with significantly reduced responses to odor stimuli on day 1, further supporting early behavioral dysfunction. In contrast, AWA neuron did not exhibit reduced calcium responses, consistent with the absence of detectable decreases in olfactory sensitivity in these neurons. These findings suggest that decreased calcium signaling and dysfunction in specific sensory neuron subtypes are early indicators of neurodegeneration in C. elegans, occurring prior to the formation of visible protein aggregates. We found that the ER unfolded protein response (UPR) is significantly activated in worms expressing Aβ1-42. Activation of the AMPK pathway alleviates olfactory defects and reduces fibrillar Aβ in these worms. This study underscores the use of C. elegans olfactory neurons as a model to elucidate mechanisms of proteostasis in neurodegenerative diseases and highlights the importance of integrated approaches.
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Affiliation(s)
- Weikang Xue
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Ziyi Lei
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Bin Liu
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Hanxin Guo
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Weiyi Yan
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Youngnam N. Jin
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Yanxun V. Yu
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
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Kramer TS, Wan FK, Pugliese SM, Atanas AA, Hiser AW, Luo J, Bueno E, Flavell SW. Neural Sequences Underlying Directed Turning in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.11.607076. [PMID: 39149398 PMCID: PMC11326294 DOI: 10.1101/2024.08.11.607076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Complex behaviors like navigation rely on sequenced motor outputs that combine to generate effective movement. The brain-wide organization of the circuits that integrate sensory signals to select and execute appropriate motor sequences is not well understood. Here, we characterize the architecture of neural circuits that control C. elegans olfactory navigation. We identify error-correcting turns during navigation and use whole-brain calcium imaging and cell-specific perturbations to determine their neural underpinnings. These turns occur as motor sequences accompanied by neural sequences, in which defined neurons activate in a stereotyped order during each turn. Distinct neurons in this sequence respond to sensory cues, anticipate upcoming turn directions, and drive movement, linking key features of this sensorimotor behavior across time. The neuromodulator tyramine coordinates these sequential brain dynamics. Our results illustrate how neuromodulation can act on a defined neural architecture to generate sequential patterns of activity that link sensory cues to motor actions.
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Affiliation(s)
- Talya S. Kramer
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- MIT Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Flossie K. Wan
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sarah M. Pugliese
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Adam A. Atanas
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alex W. Hiser
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric Bueno
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Steven W. Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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6
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Haley JA, Chalasani SH. C. elegans foraging as a model for understanding the neuronal basis of decision-making. Cell Mol Life Sci 2024; 81:252. [PMID: 38849591 PMCID: PMC11335288 DOI: 10.1007/s00018-024-05223-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 06/09/2024]
Abstract
Animals have evolved to seek, select, and exploit food sources in their environment. Collectively termed foraging, these ubiquitous behaviors are necessary for animal survival. As a foundation for understanding foraging, behavioral ecologists established early theoretical and mathematical frameworks which have been subsequently refined and supported by field and laboratory studies of foraging animals. These simple models sought to explain how animals decide which strategies to employ when locating food, what food items to consume, and when to explore the environment for new food sources. These foraging decisions involve integration of prior experience with multimodal sensory information about the animal's current environment and internal state. We suggest that the nematode Caenorhabditis elegans is well-suited for a high-resolution analysis of complex goal-oriented behaviors such as foraging. We focus our discussion on behavioral studies highlighting C. elegans foraging on bacteria and summarize what is known about the underlying neuronal and molecular pathways. Broadly, we suggest that this simple model system can provide a mechanistic understanding of decision-making and present additional avenues for advancing our understanding of complex behavioral processes.
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Affiliation(s)
- Jessica A Haley
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, 92093, USA
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Sreekanth H Chalasani
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
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7
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Philbrook A, O'Donnell MP, Grunenkovaite L, Sengupta P. Differential modulation of sensory response dynamics by cilia structure and intraflagellar transport within and across chemosensory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594529. [PMID: 38798636 PMCID: PMC11118401 DOI: 10.1101/2024.05.16.594529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Sensory neurons contain morphologically diverse primary cilia that are built by intraflagellar transport (IFT) and house sensory signaling molecules. Since both ciliary structural and signaling proteins are trafficked via IFT, it has been challenging to decouple the contributions of IFT and cilia structure to neuronal responses. By acutely inhibiting IFT without altering cilia structure and vice versa , here we describe the differential roles of ciliary trafficking and sensory ending morphology in shaping chemosensory responses in C. elegans. We show that a minimum cilium length but not continuous IFT is necessary for a subset of responses in the ASH nociceptive neurons. In contrast, neither cilia nor continuous IFT are necessary for odorant responses in the AWA olfactory neurons. Instead, continuous IFT differentially modulates response dynamics in AWA. Upon acute inhibition of IFT, cilia-destined odorant receptors are shunted to ectopic branches emanating from the cilia base. Spatial segregation of receptors in these branches from a cilia-restricted regulatory kinase results in odorant desensitization defects, highlighting the importance of precise organization of signaling molecules at sensory endings in regulating response dynamics. We also find that adaptation of AWA responses upon repeated exposure to an odorant is mediated by IFT-driven removal of its cognate receptor, whereas adaptation to a second odorant is regulated via IFT-independent mechanisms. Our results reveal unexpected complexity in the contribution of IFT and cilia organization to the regulation of responses even within a single chemosensory neuron type, and establish a critical role for these processes in the precise modulation of olfactory behaviors.
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8
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Nicoletti M, Chiodo L, Loppini A, Liu Q, Folli V, Ruocco G, Filippi S. Biophysical modeling of the whole-cell dynamics of C. elegans motor and interneurons families. PLoS One 2024; 19:e0298105. [PMID: 38551921 PMCID: PMC10980225 DOI: 10.1371/journal.pone.0298105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 01/13/2024] [Indexed: 04/01/2024] Open
Abstract
The nematode Caenorhabditis elegans is a widely used model organism for neuroscience. Although its nervous system has been fully reconstructed, the physiological bases of single-neuron functioning are still poorly explored. Recently, many efforts have been dedicated to measuring signals from C. elegans neurons, revealing a rich repertoire of dynamics, including bistable responses, graded responses, and action potentials. Still, biophysical models able to reproduce such a broad range of electrical responses lack. Realistic electrophysiological descriptions started to be developed only recently, merging gene expression data with electrophysiological recordings, but with a large variety of cells yet to be modeled. In this work, we contribute to filling this gap by providing biophysically accurate models of six classes of C. elegans neurons, the AIY, RIM, and AVA interneurons, and the VA, VB, and VD motor neurons. We test our models by comparing computational and experimental time series and simulate knockout neurons, to identify the biophysical mechanisms at the basis of inter and motor neuron functioning. Our models represent a step forward toward the modeling of C. elegans neuronal networks and virtual experiments on the nematode nervous system.
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Affiliation(s)
- Martina Nicoletti
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Istituto Italiano di Tecnologia, Rome, Italy
| | - Letizia Chiodo
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alessandro Loppini
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Qiang Liu
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Viola Folli
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Istituto Italiano di Tecnologia, Rome, Italy
- D-tails s.r.l., Rome, Italy
| | - Giancarlo Ruocco
- Center for Life Nano- & Neuro-Science (CLN2S@Sapienza), Istituto Italiano di Tecnologia, Rome, Italy
| | - Simonetta Filippi
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
- Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (CNR-INO), Florence, Italy
- ICRANet—International Center for Relativistic Astrophysics Network, Pescara, Italy
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9
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Jee Lee H, Vallier J, Lu H. Microfluidic Localized Hydrogel Polymerization Enables Simultaneous Recording of Neural Activity and Behavior in C. elegans. REACT CHEM ENG 2024; 9:666-676. [PMID: 38680986 PMCID: PMC11046317 DOI: 10.1039/d3re00516j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
Monitoring an animal's brain activity during motion provides a means to interpret the brain activity in the context of movement. However, it is challenging to obtain information about the animal's movement during neural imaging in the popular model organism C. elegans due to its small size. Here, we present a microfluidic tool to immobilize only the head region of C. elegans for simultaneous recording of neuronal activity and tail movement. We combine hydrogel photopolymerization and microfluidics to realize controlled head immobilization in a semi-continuous fashion. To optimize the immobilization process, we characterize the hydrogel polymerization under different experimental conditions, including under the effect of fluid flow. We show that the Damköhler number specifically defined for our reactive transport phenomena can predict the success of such photopolymerized hydrogels used for sample immobilization. In addition to simultaneous recording of neural activity and behavior in C. elegans, we demonstrate our method's capability to temporarily reconfigure fluid flow and deliver chemical stimuli to the animal's nose to examine the animal's responses. We envision this approach to be useful for similar recordings for other small motile organisms, as well as scenarios where microfluidics and polymerization are used to control flow and rection.
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Affiliation(s)
- Hyun Jee Lee
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, USA
| | - Julia Vallier
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, USA
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, USA
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10
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Palieri V, Paoli E, Wu YK, Haesemeyer M, Grunwald Kadow IC, Portugues R. The preoptic area and dorsal habenula jointly support homeostatic navigation in larval zebrafish. Curr Biol 2024; 34:489-504.e7. [PMID: 38211586 PMCID: PMC10849091 DOI: 10.1016/j.cub.2023.12.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 11/22/2023] [Accepted: 12/11/2023] [Indexed: 01/13/2024]
Abstract
Animals must maintain physiological processes within an optimal temperature range despite changes in their environment. Through behavioral assays, whole-brain functional imaging, and neural ablations, we show that larval zebrafish, an ectothermic vertebrate, achieves thermoregulation through homeostatic navigation-non-directional and directional movements toward the temperature closest to its physiological setpoint. A brain-wide circuit encompassing several brain regions enables this behavior. We identified the preoptic area of the hypothalamus (PoA) as a key brain structure in triggering non-directional reorientation when thermal conditions are worsening. This result shows an evolutionary conserved role of the PoA as principal thermoregulator of the brain also in ectotherms. We further show that the habenula (Hb)-interpeduncular nucleus (IPN) circuit retains a short-term memory of the sensory history to support the generation of coherent directed movements even in the absence of continuous sensory cues. We finally provide evidence that this circuit may not be exclusive for temperature but may convey a more abstract representation of relative valence of physiologically meaningful stimuli regardless of their specific identity to enable homeostatic navigation.
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Affiliation(s)
- Virginia Palieri
- Institute of Neuroscience, Technical University of Munich, Biedersteiner Strasse 29, 80802 Munich, Germany; School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Emanuele Paoli
- Institute of Neuroscience, Technical University of Munich, Biedersteiner Strasse 29, 80802 Munich, Germany
| | - You Kure Wu
- Institute of Neuroscience, Technical University of Munich, Biedersteiner Strasse 29, 80802 Munich, Germany
| | - Martin Haesemeyer
- Department of Neuroscience, The Ohio State University College of Medicine, Columbus, OH 43210, USA
| | - Ilona C Grunwald Kadow
- School of Life Sciences, Technical University of Munich, Freising, Germany; Institute of Physiology II, University of Bonn, Medical Faculty (UKB), Nussallee 11, 53115 Bonn, Germany.
| | - Ruben Portugues
- Institute of Neuroscience, Technical University of Munich, Biedersteiner Strasse 29, 80802 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), Feodor-Lynen-Str. 17, 81377 Munich, Germany.
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11
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Salim C, Batsaikhan E, Kan AK, Chen H, Jee C. Nicotine Motivated Behavior in C. elegans. Int J Mol Sci 2024; 25:1634. [PMID: 38338915 PMCID: PMC10855306 DOI: 10.3390/ijms25031634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
To maximize the advantages offered by Caenorhabditis elegans as a high-throughput (HTP) model for nicotine dependence studies, utilizing its well-defined neuroconnectome as a robust platform, and to unravel the genetic basis of nicotine-motivated behaviors, we established the nicotine conditioned cue preference (CCP) paradigm. Nicotine CCP enables the assessment of nicotine preference and seeking, revealing a parallel to fundamental aspects of nicotine-dependent behaviors observed in mammals. We demonstrated that nicotine-elicited cue preference in worms is mediated by nicotinic acetylcholine receptors and requires dopamine for CCP development. Subsequently, we pinpointed nAChR subunits associated with nicotine preference and validated human GWAS candidates linked to nicotine dependence involved in nAChRs. Functional validation involves assessing the loss-of-function strain of the CACNA2D3 ortholog and the knock-out (KO) strain of the CACNA2D2 ortholog, closely related to CACNA2D3 and sharing human smoking phenotypes. Our orthogonal approach substantiates the functional conservation of the α2δ subunit of the calcium channel in nicotine-motivated behavior. Nicotine CCP in C. elegans serves as a potent affirmation of the cross-species functional relevance of GWAS candidate genes involved in nicotine seeking associated with tobacco abuse, providing a streamlined yet comprehensive system for investigating intricate behavioral paradigms within a simplified and reliable framework.
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Affiliation(s)
| | | | | | | | - Changhoon Jee
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (C.S.)
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12
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Pu L, Wang J, Lu Q, Nilsson L, Philbrook A, Pandey A, Zhao L, Schendel RV, Koh A, Peres TV, Hashi WH, Myint SL, Williams C, Gilthorpe JD, Wai SN, Brown A, Tijsterman M, Sengupta P, Henriksson J, Chen C. Dissecting the genetic landscape of GPCR signaling through phenotypic profiling in C. elegans. Nat Commun 2023; 14:8410. [PMID: 38110404 PMCID: PMC10728192 DOI: 10.1038/s41467-023-44177-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/04/2023] [Indexed: 12/20/2023] Open
Abstract
G protein-coupled receptors (GPCRs) mediate responses to various extracellular and intracellular cues. However, the large number of GPCR genes and their substantial functional redundancy make it challenging to systematically dissect GPCR functions in vivo. Here, we employ a CRISPR/Cas9-based approach, disrupting 1654 GPCR-encoding genes in 284 strains and mutating 152 neuropeptide-encoding genes in 38 strains in C. elegans. These two mutant libraries enable effective deorphanization of chemoreceptors, and characterization of receptors for neuropeptides in various cellular processes. Mutating a set of closely related GPCRs in a single strain permits the assignment of functions to GPCRs with functional redundancy. Our analyses identify a neuropeptide that interacts with three receptors in hypoxia-evoked locomotory responses, unveil a collection of regulators in pathogen-induced immune responses, and define receptors for the volatile food-related odorants. These results establish our GPCR and neuropeptide mutant libraries as valuable resources for the C. elegans community to expedite studies of GPCR signaling in multiple contexts.
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Affiliation(s)
- Longjun Pu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Jing Wang
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Qiongxuan Lu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Lars Nilsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Alison Philbrook
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Anjali Pandey
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Lina Zhao
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Robin van Schendel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Alan Koh
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Tanara V Peres
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Weheliye H Hashi
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Si Lhyam Myint
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Chloe Williams
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | - Sun Nyunt Wai
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Andre Brown
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Piali Sengupta
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Johan Henriksson
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.
- Integrated Science Lab (Icelab), Umeå University, Umeå, Sweden.
| | - Changchun Chen
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden.
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden.
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13
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Alexander KD, Ramachandran S, Biswas K, Lambert CM, Russell J, Oliver DB, Armstrong W, Rettler M, Liu S, Doitsidou M, Bénard C, Walker AK, Francis MM. The homeodomain transcriptional regulator DVE-1 directs a program for synapse elimination during circuit remodeling. Nat Commun 2023; 14:7520. [PMID: 37980357 PMCID: PMC10657367 DOI: 10.1038/s41467-023-43281-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 11/02/2023] [Indexed: 11/20/2023] Open
Abstract
The elimination of synapses during circuit remodeling is critical for brain maturation; however, the molecular mechanisms directing synapse elimination and its timing remain elusive. We show that the transcriptional regulator DVE-1, which shares homology with special AT-rich sequence-binding (SATB) family members previously implicated in human neurodevelopmental disorders, directs the elimination of juvenile synaptic inputs onto remodeling C. elegans GABAergic neurons. Juvenile acetylcholine receptor clusters and apposing presynaptic sites are eliminated during the maturation of wild-type GABAergic neurons but persist into adulthood in dve-1 mutants, producing heightened motor connectivity. DVE-1 localization to GABAergic nuclei is required for synapse elimination, consistent with DVE-1 regulation of transcription. Pathway analysis of putative DVE-1 target genes, proteasome inhibitor, and genetic experiments implicate the ubiquitin-proteasome system in synapse elimination. Together, our findings define a previously unappreciated role for a SATB family member in directing synapse elimination during circuit remodeling, likely through transcriptional regulation of protein degradation processes.
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Affiliation(s)
- Kellianne D Alexander
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kasturi Biswas
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Julia Russell
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Devyn B Oliver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - William Armstrong
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Monika Rettler
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Samuel Liu
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Maria Doitsidou
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland
| | - Claire Bénard
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Biological Sciences, Université du Québec à Montréal, Quebec, Canada
| | - Amy K Walker
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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14
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Prakash SJ, Van Auken KM, Hill DP, Sternberg PW. Semantic representation of neural circuit knowledge in Caenorhabditis elegans. Brain Inform 2023; 10:30. [PMID: 37947958 PMCID: PMC10638142 DOI: 10.1186/s40708-023-00208-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/22/2023] [Indexed: 11/12/2023] Open
Abstract
In modern biology, new knowledge is generated quickly, making it challenging for researchers to efficiently acquire and synthesise new information from the large volume of primary publications. To address this problem, computational approaches that generate machine-readable representations of scientific findings in the form of knowledge graphs have been developed. These representations can integrate different types of experimental data from multiple papers and biological knowledge bases in a unifying data model, providing a complementary method to manual review for interacting with published knowledge. The Gene Ontology Consortium (GOC) has created a semantic modelling framework that extends individual functional gene annotations to structured descriptions of causal networks representing biological processes (Gene Ontology-Causal Activity Modelling, or GO-CAM). In this study, we explored whether the GO-CAM framework could represent knowledge of the causal relationships between environmental inputs, neural circuits and behavior in the model nematode C. elegans [C. elegans Neural-Circuit Causal Activity Modelling (CeN-CAM)]. We found that, given extensions to several relevant ontologies, a wide variety of author statements from the literature about the neural circuit basis of egg-laying and carbon dioxide (CO2) avoidance behaviors could be faithfully represented with CeN-CAM. Through this process, we were able to generate generic data models for several categories of experimental results. We also discuss how semantic modelling may be used to functionally annotate the C. elegans connectome. Thus, Gene Ontology-based semantic modelling has the potential to support various machine-readable representations of neurobiological knowledge.
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Affiliation(s)
- Sharan J Prakash
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Kimberly M Van Auken
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - David P Hill
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
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15
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Campagna CM, McMahon H, Nechipurenko I. The G protein alpha chaperone and guanine-nucleotide exchange factor RIC-8 regulates cilia morphogenesis in Caenorhabditis elegans sensory neurons. PLoS Genet 2023; 19:e1011015. [PMID: 37910589 PMCID: PMC10642896 DOI: 10.1371/journal.pgen.1011015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 11/13/2023] [Accepted: 10/12/2023] [Indexed: 11/03/2023] Open
Abstract
Heterotrimeric G (αβγ) proteins are canonical transducers of G-protein-coupled receptor (GPCR) signaling and play critical roles in communication between cells and their environment. Many GPCRs and heterotrimeric G proteins localize to primary cilia and modulate cilia morphology via mechanisms that are not well understood. Here, we show that RIC-8, a cytosolic guanine nucleotide exchange factor (GEF) and chaperone for Gα protein subunits, shapes cilia membrane morphology in a subset of Caenorhabditis elegans sensory neurons. Consistent with its role in ciliogenesis, C. elegans RIC-8 localizes to cilia in different sensory neuron types. Using domain mutagenesis, we demonstrate that while the GEF function alone is not sufficient, both the GEF and Gα-interacting chaperone motifs of RIC-8 are required for its role in cilia morphogenesis. We identify ODR-3 as the RIC-8 Gα client and demonstrate that RIC-8 functions in the same genetic pathway with another component of the non-canonical G protein signaling AGS-3 to shape cilia morphology. Notably, despite defects in AWC cilia morphology, ags-3 null mutants exhibit normal chemotaxis toward benzaldehyde unlike odr-3 mutant animals. Collectively, our findings describe a novel function for the evolutionarily conserved protein RIC-8 and non-canonical RIC-8-AGS-3-ODR-3 signaling in cilia morphogenesis and uncouple Gα ODR-3 functions in ciliogenesis and olfaction.
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Affiliation(s)
- Christina M. Campagna
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Hayley McMahon
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Inna Nechipurenko
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
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16
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Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Meng B, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. Curr Biol 2023; 33:4430-4445.e6. [PMID: 37769660 PMCID: PMC10860333 DOI: 10.1016/j.cub.2023.08.088] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/24/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior.
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Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Casey M Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bohan Meng
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexandra B Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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17
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Prakash SJ, Van Auken KM, Hill DP, Sternberg PW. Semantic Representation of Neural Circuit Knowledge in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.28.538760. [PMID: 37162850 PMCID: PMC10168330 DOI: 10.1101/2023.04.28.538760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In modern biology, new knowledge is generated quickly, making it challenging for researchers to efficiently acquire and synthesise new information from the large volume of primary publications. To address this problem, computational approaches that generate machine-readable representations of scientific findings in the form of knowledge graphs have been developed. These representations can integrate different types of experimental data from multiple papers and biological knowledge bases in a unifying data model, providing a complementary method to manual review for interacting with published knowledge. The Gene Ontology Consortium (GOC) has created a semantic modelling framework that extends individual functional gene annotations to structured descriptions of causal networks representing biological processes (Gene Ontology Causal Activity Modelling, or GO-CAM). In this study, we explored whether the GO-CAM framework could represent knowledge of the causal relationships between environmental inputs, neural circuits and behavior in the model nematode C. elegans (C. elegans Neural Circuit Causal Activity Modelling (CeN-CAM)). We found that, given extensions to several relevant ontologies, a wide variety of author statements from the literature about the neural circuit basis of egg-laying and carbon dioxide (CO2) avoidance behaviors could be faithfully represented with CeN-CAM. Through this process, we were able to generate generic data models for several categories of experimental results. We also discuss how semantic modelling may be used to functionally annotate the C. elegans connectome. Thus, Gene Ontology-based semantic modelling has the potential to support various machine-readable representations of neurobiological knowledge.
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Affiliation(s)
- Sharan J Prakash
- 1. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kimberly M Van Auken
- 1. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - David P Hill
- 2. The Jackson Laboratory, Bar Harbor, ME, 04609 USA
| | - Paul W Sternberg
- 1. Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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18
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Wang L, Zhao J, Xiong X, Li L, Zhu T, Pei H. Enzyme-Free Nucleic Acid Circuits for Fold-Change Detection. Chempluschem 2023; 88:e202300083. [PMID: 37005227 DOI: 10.1002/cplu.202300083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 04/04/2023]
Abstract
Fold-change detection is widespread in sensory systems of various organisms. Dynamic DNA nanotechnology provides an important toolbox for reproducing structures and responses of cellular circuits. In this work, we construct an enzyme-free nucleic acid circuit based on the incoherent feed-forward loop using toehold-mediated DNA strand displacement reactions and explore its dynamic behaviors. The mathematical model based on ordinary differential equations is used to evaluate the parameter regime required for fold-change detection. After selecting appropriate parameters, the constructed synthetic circuit exhibits approximate fold-change detection for multiple rounds of inputs with different initial concentrations. This work is anticipated to shed new light on the design of DNA dynamic circuits in the enzyme-free environment.
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Affiliation(s)
- Likun Wang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
| | - Jiayan Zhao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
| | - Xiewei Xiong
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
| | - Li Li
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
| | - Tong Zhu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
| | - Hao Pei
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241 (P. R., China
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19
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Campagna CM, McMahon H, Nechipurenko I. The G protein alpha Chaperone and Guanine-Nucleotide Exchange Factor RIC-8 Regulates Cilia Morphogenesis in Caenorhabditis elegans Sensory Neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554856. [PMID: 37662329 PMCID: PMC10473713 DOI: 10.1101/2023.08.25.554856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Heterotrimeric G (αβγ) proteins are canonical transducers of G-protein-coupled receptor (GPCR) signaling and play critical roles in communication between cells and their environment. Many GPCRs and heterotrimeric G proteins localize to primary cilia and modulate cilia morphology via mechanisms that are not well understood. Here, we show that RIC-8, a cytosolic guanine nucleotide exchange factor (GEF) and chaperone for Gα protein subunits, shapes cilia membrane morphology in a subset of Caenorhabditis elegans sensory neurons. Consistent with its role in ciliogenesis, C. elegans RIC-8 localizes to cilia in different sensory neuron types. Using domain mutagenesis, we demonstrate that while the GEF function alone is not sufficient, both the GEF and Gα-interacting chaperone motifs of RIC-8 are required for its role in cilia morphogenesis. We identify ODR-3 as the RIC-8 Gα client and demonstrate that RIC-8 functions in the same genetic pathway with another component of the non-canonical G protein signaling AGS-3 to shape cilia morphology. Notably, despite severe defects in AWC cilia morphology, ags-3 null mutants exhibit normal chemotaxis toward benzaldehyde unlike odr-3 mutant animals. Collectively, our findings describe a novel function for the evolutionarily conserved protein RIC-8 and non-canonical RIC-8-AGS-3-ODR-3 signaling in cilia morphogenesis and uncouple Gα ODR-3 functions in ciliogenesis and olfaction.
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Affiliation(s)
- Christina M. Campagna
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Hayley McMahon
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Inna Nechipurenko
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
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20
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Madirolas G, Al-Asmar A, Gaouar L, Marie-Louise L, Garza-Enríquez A, Rodríguez-Rada V, Khona M, Dal Bello M, Ratzke C, Gore J, Pérez-Escudero A. Caenorhabditis elegans foraging patterns follow a simple rule of thumb. Commun Biol 2023; 6:841. [PMID: 37580527 PMCID: PMC10425387 DOI: 10.1038/s42003-023-05220-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 08/04/2023] [Indexed: 08/16/2023] Open
Abstract
Rules of thumb are behavioral algorithms that approximate optimal behavior while lowering cognitive and sensory costs. One way to reduce these costs is by simplifying the representation of the environment: While the theoretically optimal behavior may depend on many environmental variables, a rule of thumb may use a smaller set of variables that performs reasonably well. Experimental proof of this simplification requires an exhaustive mapping of all relevant combinations of several environmental parameters, which we performed for Caenorhabditis elegans foraging by covering systematically combinations of food density (across 4 orders of magnitude) and food type (across 12 bacterial strains). We found that worms' response is dominated by a single environmental variable: food density measured as number of bacteria per unit surface. They disregard other factors such as biomass content or bacterial strain. We also measured experimentally the impact on fitness of each type of food, determining that the rule is near-optimal and therefore constitutes a rule of thumb that leverages the most informative environmental variable. These results set the stage for further investigations into the underlying genetic and neural mechanisms governing this simplification process, and into its role in the evolution of decision-making strategies.
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Affiliation(s)
- Gabriel Madirolas
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Alid Al-Asmar
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Lydia Gaouar
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Leslie Marie-Louise
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Andrea Garza-Enríquez
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Valentina Rodríguez-Rada
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Mikail Khona
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Martina Dal Bello
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christoph Ratzke
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Cluster of Excellence EXC 2124 "Controlling Microbes to Fight Infections" (CMFI), University of Tübingen, Calwerstrasse 7/1, 72076, Tübingen, Germany
| | - Jeff Gore
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alfonso Pérez-Escudero
- Centre de Recherches sur la Cognition Animale (UMR5169), Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, 31062, France.
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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21
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Chen KS, Wu R, Gershow MH, Leifer AM. Continuous odor profile monitoring to study olfactory navigation in small animals. eLife 2023; 12:e85910. [PMID: 37489570 PMCID: PMC10425172 DOI: 10.7554/elife.85910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023] Open
Abstract
Olfactory navigation is observed across species and plays a crucial role in locating resources for survival. In the laboratory, understanding the behavioral strategies and neural circuits underlying odor-taxis requires a detailed understanding of the animal's sensory environment. For small model organisms like Caenorhabditis elegans and larval Drosophila melanogaster, controlling and measuring the odor environment experienced by the animal can be challenging, especially for airborne odors, which are subject to subtle effects from airflow, temperature variation, and from the odor's adhesion, adsorption, or reemission. Here, we present a method to control and measure airborne odor concentration in an arena compatible with an agar substrate. Our method allows continuous controlling and monitoring of the odor profile while imaging animal behavior. We construct stationary chemical landscapes in an odor flow chamber through spatially patterned odorized air. The odor concentration is measured with a spatially distributed array of digital gas sensors. Careful placement of the sensors allows the odor concentration across the arena to be continuously inferred in space and monitored through time. We use this approach to measure the odor concentration that each animal experiences as it undergoes chemotaxis behavior and report chemotaxis strategies for C. elegans and D. melanogaster larvae populations as they navigate spatial odor landscapes.
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Affiliation(s)
- Kevin S Chen
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
| | - Rui Wu
- Department of Physics, New York UniversityNew YorkUnited States
| | - Marc H Gershow
- Department of Physics, New York UniversityNew YorkUnited States
- Center for Neural Science, New York UniversityNew YorkUnited States
| | - Andrew M Leifer
- Princeton Neuroscience Institute, Princeton UniversityPrincetonUnited States
- Department of Physics, Princeton UniversityPrincetonUnited States
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22
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Sawicki J, Berner R, Loos SAM, Anvari M, Bader R, Barfuss W, Botta N, Brede N, Franović I, Gauthier DJ, Goldt S, Hajizadeh A, Hövel P, Karin O, Lorenz-Spreen P, Miehl C, Mölter J, Olmi S, Schöll E, Seif A, Tass PA, Volpe G, Yanchuk S, Kurths J. Perspectives on adaptive dynamical systems. CHAOS (WOODBURY, N.Y.) 2023; 33:071501. [PMID: 37486668 DOI: 10.1063/5.0147231] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/24/2023] [Indexed: 07/25/2023]
Abstract
Adaptivity is a dynamical feature that is omnipresent in nature, socio-economics, and technology. For example, adaptive couplings appear in various real-world systems, such as the power grid, social, and neural networks, and they form the backbone of closed-loop control strategies and machine learning algorithms. In this article, we provide an interdisciplinary perspective on adaptive systems. We reflect on the notion and terminology of adaptivity in different disciplines and discuss which role adaptivity plays for various fields. We highlight common open challenges and give perspectives on future research directions, looking to inspire interdisciplinary approaches.
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Affiliation(s)
- Jakub Sawicki
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Akademie Basel, Fachhochschule Nordwestschweiz FHNW, Leonhardsstrasse 6, 4009 Basel, Switzerland
| | - Rico Berner
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Sarah A M Loos
- DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom
| | - Mehrnaz Anvari
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Fraunhofer Institute for Algorithms and Scientific Computing, Schloss Birlinghoven, 53757 Sankt-Augustin, Germany
| | - Rolf Bader
- Institute of Systematic Musicology, University of Hamburg, Hamburg, Germany
| | - Wolfram Barfuss
- Transdisciplinary Research Area: Sustainable Futures, University of Bonn, 53113 Bonn, Germany
- Center for Development Research (ZEF), University of Bonn, 53113 Bonn, Germany
| | - Nicola Botta
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Department of Computer Science and Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Nuria Brede
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Department of Computer Science, University of Potsdam, An der Bahn 2, 14476 Potsdam, Germany
| | - Igor Franović
- Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Daniel J Gauthier
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
| | - Sebastian Goldt
- Department of Physics, International School of Advanced Studies (SISSA), Trieste, Italy
| | - Aida Hajizadeh
- Research Group Comparative Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Philipp Hövel
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
| | - Omer Karin
- Department of Mathematics, Imperial College London, London SW7 2AZ, United Kingdom
| | - Philipp Lorenz-Spreen
- Center for Adaptive Rationality, Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany
| | - Christoph Miehl
- Akademie Basel, Fachhochschule Nordwestschweiz FHNW, Leonhardsstrasse 6, 4009 Basel, Switzerland
| | - Jan Mölter
- Department of Mathematics, School of Computation, Information and Technology, Technical University of Munich, Boltzmannstraße 3, 85748 Garching bei München, Germany
| | - Simona Olmi
- Akademie Basel, Fachhochschule Nordwestschweiz FHNW, Leonhardsstrasse 6, 4009 Basel, Switzerland
| | - Eckehard Schöll
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Akademie Basel, Fachhochschule Nordwestschweiz FHNW, Leonhardsstrasse 6, 4009 Basel, Switzerland
| | - Alireza Seif
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
| | - Peter A Tass
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94304, USA
| | - Giovanni Volpe
- Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Serhiy Yanchuk
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Jürgen Kurths
- Potsdam Institute for Climate Impact Research, Telegrafenberg, 14473 Potsdam, Germany
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
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23
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Zhang J, Yang W, Li Z, Huang F, Zhang K. Multigenerational exposure of cadmium trans-generationally impairs locomotive and chemotactic behaviors in Caenorhabditis elegans. CHEMOSPHERE 2023; 325:138432. [PMID: 36933370 DOI: 10.1016/j.chemosphere.2023.138432] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/19/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Cadmium is a naturally existing heavy metal and a notorious environmental pollutant. While its toxic outcomes and underlying mechanisms remain largely elusive. To explore the behavioral change caused by multigenerational exposure of cadmium to C. elegans, we challenged the C. elegans with cadmium for six generations and observed its impact on animal behaviors. Wild-type worms were randomly divided into two groups, the control and cadmium exposure groups. Locomotive and chemotactic behaviors were observed across six generations. Head thrashing frequency, chemotaxis index, and fold change index were used to evaluate the neurotoxicity of multigenerational cadmium exposure. Multigenerational cadmium exposure can trans-generationally increase the head thrashing frequency of C. elegans during swimming, and impair the chemotactic behaviors to isoamyl alcohol, diacetyl, and 2-nonanone. Our findings proposed a trans-generationally behavioral impact induced by multigenerational cadmium exposure.
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Affiliation(s)
- Jun Zhang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Wenxing Yang
- Department of Physiology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Zhuo Li
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Feijun Huang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Kui Zhang
- Department of Forensic Pathology, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610041, PR China.
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24
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Pritz C, Itskovits E, Bokman E, Ruach R, Gritsenko V, Nelken T, Menasherof M, Azulay A, Zaslaver A. Principles for coding associative memories in a compact neural network. eLife 2023; 12:e74434. [PMID: 37140557 PMCID: PMC10159626 DOI: 10.7554/elife.74434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 03/08/2023] [Indexed: 05/05/2023] Open
Abstract
A major goal in neuroscience is to elucidate the principles by which memories are stored in a neural network. Here, we have systematically studied how four types of associative memories (short- and long-term memories, each as positive and negative associations) are encoded within the compact neural network of Caenorhabditis elegans worms. Interestingly, sensory neurons were primarily involved in coding short-term, but not long-term, memories, and individual sensory neurons could be assigned to coding either the conditioned stimulus or the experience valence (or both). Moreover, when considering the collective activity of the sensory neurons, the specific training experiences could be decoded. Interneurons integrated the modulated sensory inputs and a simple linear combination model identified the experience-specific modulated communication routes. The widely distributed memory suggests that integrated network plasticity, rather than changes to individual neurons, underlies the fine behavioral plasticity. This comprehensive study reveals basic memory-coding principles and highlights the central roles of sensory neurons in memory formation.
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Affiliation(s)
- Christian Pritz
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Eyal Itskovits
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Eduard Bokman
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Rotem Ruach
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Vladimir Gritsenko
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Tal Nelken
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Mai Menasherof
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Aharon Azulay
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Alon Zaslaver
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
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25
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Porta-de-la-Riva M, Gonzalez AC, Sanfeliu-Cerdán N, Karimi S, Malaiwong N, Pidde A, Morales-Curiel LF, Fernandez P, González-Bolívar S, Hurth C, Krieg M. Neural engineering with photons as synaptic transmitters. Nat Methods 2023; 20:761-769. [PMID: 37024651 DOI: 10.1038/s41592-023-01836-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 03/03/2023] [Indexed: 04/08/2023]
Abstract
Neuronal computation is achieved through connections of individual neurons into a larger network. To expand the repertoire of endogenous cellular communication, we developed a synthetic, photon-assisted synaptic transmission (PhAST) system. PhAST is based on luciferases and channelrhodopsins that enable the transmission of a neuronal state across space, using photons as neurotransmitters. PhAST overcomes synaptic barriers and rescues the behavioral deficit of a glutamate mutant with conditional, calcium-triggered photon emission between two neurons of the Caenorhabditis elegans nociceptive avoidance circuit. To demonstrate versatility and flexibility, we generated de novo synaptic transmission between two unconnected cells in a sexually dimorphic neuronal circuit, suppressed endogenous nocifensive response through activation of an anion channelrhodopsin and switched attractive to aversive behavior in an olfactory circuit. Finally, we applied PhAST to dissect the calcium dynamics of the temporal pattern generator in a motor circuit for ovipositioning. In summary, we established photon-based synaptic transmission that facilitates the modification of animal behavior.
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Affiliation(s)
| | | | | | - Shadi Karimi
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | | | | | | | | | | | - Cedric Hurth
- Institut de Ciències Fotòniques, Castelldefels, Spain
| | - Michael Krieg
- Institut de Ciències Fotòniques, Castelldefels, Spain.
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26
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Ikejiri Y, Tanimoto Y, Fujita K, Hiramatsu F, Yamazaki SJ, Endo Y, Iwatani Y, Fujimoto K, Kimura KD. Neural mechanism of experience-dependent sensory gain control in C. elegans. Neurosci Res 2023; 191:77-90. [PMID: 36681153 DOI: 10.1016/j.neures.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Animals' sensory systems adjust their responsiveness to environmental stimuli that vary greatly in their intensity. Here we report the neural mechanism of experience-dependent sensory adjustment, especially gain control, in the ASH nociceptive neurons in Caenorhabditis elegans. Using calcium imaging under gradual changes in stimulus intensity, we find that the ASH neurons of naive animals respond to concentration increases in a repulsive odor 2-nonanone regardless of the magnitude of the concentration increase. However, after preexposure to the odor, the ASH neurons exhibit significantly weak responses to a small gradual increase in odor concentration while their responses to a large gradual increase remain strong. Thus, preexposure changes the slope of stimulus-response relationships (i.e., gain control). Behavioral analysis suggests that this gain control contributes to the preexposure-dependent enhancement of odor avoidance behavior. Mathematical analysis reveals that the ASH response consists of fast and slow components, and that the fast component is specifically suppressed by preexposure for the gain control. In addition, genetic analysis suggests that G protein signaling may be required for the regulation of fast component. We propose how prior experience dynamically and specifically modulates stimulus-response relationships in sensory neurons, eventually leading to adaptive modulation of behavior.
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Affiliation(s)
- Yosuke Ikejiri
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuki Tanimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kosuke Fujita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Fumie Hiramatsu
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Shuhei J Yamazaki
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuto Endo
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yasushi Iwatani
- Department of Science and Technology, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Koichi Fujimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Koutarou D Kimura
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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27
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Wu T, Ge M, Wu M, Duan F, Liang J, Chen M, Gracida X, Liu H, Yang W, Dar AR, Li C, Butcher RA, Saltzman AL, Zhang Y. Pathogenic bacteria modulate pheromone response to promote mating. Nature 2023; 613:324-331. [PMID: 36599989 PMCID: PMC10732163 DOI: 10.1038/s41586-022-05561-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 11/11/2022] [Indexed: 01/05/2023]
Abstract
Pathogens generate ubiquitous selective pressures and host-pathogen interactions alter social behaviours in many animals1-4. However, very little is known about the neuronal mechanisms underlying pathogen-induced changes in social behaviour. Here we show that in adult Caenorhabditis elegans hermaphrodites, exposure to a bacterial pathogen (Pseudomonas aeruginosa) modulates sensory responses to pheromones by inducing the expression of the chemoreceptor STR-44 to promote mating. Under standard conditions, C. elegans hermaphrodites avoid a mixture of ascaroside pheromones to facilitate dispersal5-13. We find that exposure to the pathogenic Pseudomonas bacteria enables pheromone responses in AWA sensory neurons, which mediate attractive chemotaxis, to suppress the avoidance. Pathogen exposure induces str-44 expression in AWA neurons, a process regulated by a transcription factor zip-5 that also displays a pathogen-induced increase in expression in AWA. STR-44 acts as a pheromone receptor and its function in AWA neurons is required for pathogen-induced AWA pheromone response and suppression of pheromone avoidance. Furthermore, we show that C. elegans hermaphrodites, which reproduce mainly through self-fertilization, increase the rate of mating with males after pathogen exposure and that this increase requires str-44 in AWA neurons. Thus, our results uncover a causal mechanism for pathogen-induced social behaviour plasticity, which can promote genetic diversity and facilitate adaptation of the host animals.
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Affiliation(s)
- Taihong Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Minghai Ge
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Min Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Fengyun Duan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Jingting Liang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Maoting Chen
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Xicotencatl Gracida
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - He Liu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Wenxing Yang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Abdul Rouf Dar
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Chengyin Li
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Arneet L Saltzman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
- Center for Brain Science, Harvard University, Cambridge, MA, USA.
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28
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A reinforcement learning fuzzy system for continuous control in robotic odor plume tracking. ROBOTICA 2022. [DOI: 10.1017/s0263574722001321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
In dynamic outdoor environments characterized by turbulent airflow and intermittent odor plumes, robotic odor plume tracking remains challenging, because existing algorithms heavily rely on manually tuning or learning from expert experience, which are hard to implement in an unknown environment. In this paper, a multi-continuous-output Takagi–Sugeno–Kang fuzzy system was designed and tuned with reinforcement learning to solve the robotic odor source localization problem in dynamic odor plumes. Based on the Lévy Taxis plume tracking controller, the proposed fuzzy system determined the parameters of the controller based on the robot’s observation and guided the robot to turn and move towards the odor source at each searching step. The trained fuzzy system was tested in simulated filament-based odor plumes dispersed by a changing wind field. The results showed that the performance of the proposed fuzzy system-based controller trained with reinforcement learning can achieve a similar success rate and higher efficiency compared with a manually tuned and well-designed fuzzy system-based controller. The fuzzy system-based plume tracking controller was also validated through real robotic experiments.
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29
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Ruach R, Yellinek S, Itskovits E, Deshe N, Eliezer Y, Bokman E, Zaslaver A. A negative feedback loop in the GPCR pathway underlies efficient coding of external stimuli. Mol Syst Biol 2022; 18:e10514. [PMID: 36106925 PMCID: PMC9476886 DOI: 10.15252/msb.202110514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
Efficient navigation based on chemical cues is an essential feature shared by all animals. These cues may be encountered in complex spatiotemporal patterns and with orders of magnitude varying intensities. Nevertheless, sensory neurons accurately extract the relevant information from such perplexing signals. Here, we show how a single sensory neuron in Caenorhabditis elegans animals can cell-autonomously encode complex stimulus patterns composed of instantaneous sharp changes and of slowly changing continuous gradients. This encoding relies on a simple negative feedback in the G-protein-coupled receptor (GPCR) signaling pathway in which TAX-6/Calcineurin plays a key role in mediating the feedback inhibition. This negative feedback supports several important coding features that underlie an efficient navigation strategy, including exact adaptation and adaptation to the magnitude of the gradient's first derivative. A simple mathematical model explains the fine neural dynamics of both wild-type and tax-6 mutant animals, further highlighting how the calcium-dependent activity of TAX-6/Calcineurin dictates GPCR inhibition and response dynamics. As GPCRs are ubiquitously expressed in all sensory neurons, this mechanism may be a general solution for efficient cell-autonomous coding of external stimuli.
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Affiliation(s)
- Rotem Ruach
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Shai Yellinek
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Eyal Itskovits
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Noa Deshe
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Yifat Eliezer
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Eduard Bokman
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
| | - Alon Zaslaver
- Department of Genetics, Silberman Institute of Life Science, Edmond J. Safra CampusThe Hebrew UniversityJerusalemIsrael
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30
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Riedl J, Fieseler C, Zimmer M. Tyraminergic corollary discharge filters reafferent perception in a chemosensory neuron. Curr Biol 2022; 32:3048-3058.e6. [PMID: 35690069 DOI: 10.1016/j.cub.2022.05.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/10/2022] [Accepted: 05/18/2022] [Indexed: 12/25/2022]
Abstract
Interpreting sensory information requires its integration with the current behavior of the animal. However, how motor-related circuits influence sensory information processing is incompletely understood. Here, we report that current locomotor state directly modulates the activity of BAG CO2 sensory neurons in Caenorhabditis elegans. By recording neuronal activity in animals freely navigating CO2 landscapes, we found that during reverse crawling states, BAG activity is suppressed by tyraminergic corollary discharge signaling. We provide genetic evidence that tyramine released from the RIM reversal interneurons extrasynaptically activates the inhibitory chloride channel LGC-55 in BAG. Disrupting this pathway genetically leads to excessive behavioral responses to CO2 stimuli. Moreover, we find that LGC-55 signaling cancels out perception of self-produced CO2 and O2 stimuli when animals reverse into their own gas plume in ethologically relevant aqueous environments. Our results show that sensorimotor integration involves corollary discharge signals directly modulating chemosensory neurons.
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Affiliation(s)
- Julia Riedl
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Charles Fieseler
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Manuel Zimmer
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria; Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
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31
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Zjacic N, Scholz M. The role of food odor in invertebrate foraging. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12793. [PMID: 34978135 PMCID: PMC9744530 DOI: 10.1111/gbb.12793] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/01/2021] [Accepted: 12/18/2021] [Indexed: 11/30/2022]
Abstract
Foraging for food is an integral part of animal survival. In small insects and invertebrates, multisensory information and optimized locomotion strategies are used to effectively forage in patchy and complex environments. Here, the importance of olfactory cues for effective invertebrate foraging is discussed in detail. We review how odors are used by foragers to move toward a likely food source and the recent models that describe this sensory-driven behavior. We argue that smell serves a second function by priming an organism for the efficient exploitation of food. By appraising food odors, invertebrates can establish preferences and better adapt to their ecological niches, thereby promoting survival. The smell of food pre-prepares the gastrointestinal system and primes feeding motor programs for more effective ingestion as well. Optimizing resource utilization affects longevity and reproduction as a result, leading to drastic changes in survival. We propose that models of foraging behavior should include odor priming, and illustrate this with a simple toy model based on the marginal value theorem. Lastly, we discuss the novel techniques and assays in invertebrate research that could investigate the interactions between odor sensing and food intake. Overall, the sense of smell is indispensable for efficient foraging and influences not only locomotion, but also organismal physiology, which should be reflected in behavioral modeling.
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Affiliation(s)
- Nicolina Zjacic
- Max Planck Research Group Neural Information FlowCenter of Advanced European Studies and Research (Caesar)BonnGermany
| | - Monika Scholz
- Max Planck Research Group Neural Information FlowCenter of Advanced European Studies and Research (Caesar)BonnGermany
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32
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Ji N, Madan GK, Fabre GI, Dayan A, Baker CM, Kramer TS, Nwabudike I, Flavell SW. A neural circuit for flexible control of persistent behavioral states. eLife 2021; 10:e62889. [PMID: 34792019 PMCID: PMC8660023 DOI: 10.7554/elife.62889] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/17/2021] [Indexed: 11/29/2022] Open
Abstract
To adapt to their environments, animals must generate behaviors that are closely aligned to a rapidly changing sensory world. However, behavioral states such as foraging or courtship typically persist over long time scales to ensure proper execution. It remains unclear how neural circuits generate persistent behavioral states while maintaining the flexibility to select among alternative states when the sensory context changes. Here, we elucidate the functional architecture of a neural circuit controlling the choice between roaming and dwelling states, which underlie exploration and exploitation during foraging in C. elegans. By imaging ensemble-level neural activity in freely moving animals, we identify stereotyped changes in circuit activity corresponding to each behavioral state. Combining circuit-wide imaging with genetic analysis, we find that mutual inhibition between two antagonistic neuromodulatory systems underlies the persistence and mutual exclusivity of the neural activity patterns observed in each state. Through machine learning analysis and circuit perturbations, we identify a sensory processing neuron that can transmit information about food odors to both the roaming and dwelling circuits and bias the animal towards different states in different sensory contexts, giving rise to context-appropriate state transitions. Our findings reveal a potentially general circuit architecture that enables flexible, sensory-driven control of persistent behavioral states.
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Affiliation(s)
- Ni Ji
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Gurrein K Madan
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Guadalupe I Fabre
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Alyssa Dayan
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Casey M Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Talya S Kramer
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
- MIT Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, United States
| | - Ijeoma Nwabudike
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
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33
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How JJ, Navlakha S, Chalasani SH. Neural network features distinguish chemosensory stimuli in Caenorhabditis elegans. PLoS Comput Biol 2021; 17:e1009591. [PMID: 34752447 PMCID: PMC8604368 DOI: 10.1371/journal.pcbi.1009591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 11/19/2021] [Accepted: 10/26/2021] [Indexed: 11/19/2022] Open
Abstract
Nervous systems extract and process information from the environment to alter animal behavior and physiology. Despite progress in understanding how different stimuli are represented by changes in neuronal activity, less is known about how they affect broader neural network properties. We developed a framework for using graph-theoretic features of neural network activity to predict ecologically relevant stimulus properties, in particular stimulus identity. We used the transparent nematode, Caenorhabditis elegans, with its small nervous system to define neural network features associated with various chemosensory stimuli. We first immobilized animals using a microfluidic device and exposed their noses to chemical stimuli while monitoring changes in neural activity of more than 50 neurons in the head region. We found that graph-theoretic features, which capture patterns of interactions between neurons, are modulated by stimulus identity. Further, we show that a simple machine learning classifier trained using graph-theoretic features alone, or in combination with neural activity features, can accurately predict salt stimulus. Moreover, by focusing on putative causal interactions between neurons, the graph-theoretic features were almost twice as predictive as the neural activity features. These results reveal that stimulus identity modulates the broad, network-level organization of the nervous system, and that graph theory can be used to characterize these changes. Animals use their nervous systems to detect and respond to changes in their external environment. A central challenge in computational neuroscience is to determine how specific properties of these stimuli affect interactions between neurons. While most studies have focused on the neurons in the sensory periphery, recent advances allow us to probe how the rest of the nervous system responds to sensory stimulation. We recorded activity of neurons within the C. elegans head region while the animal was exposed to various chemosensory stimuli. We then used computational methods to identify various stimuli by analyzing neural activity. Specifically, we used a combination of population-level activity statistics (e.g., average, standard deviation, frequency-based measures) and graph-theoretic features of functional network structure (e.g., transitivity, which is the existence of strongly connected triplets of neurons) to accurately predict salt stimulus. Our method is general and can be used across species, particularly in instances where the identities of individual neurons are unknown. These results also suggest that neural activity downstream of the sensory periphery contains a signature of changes in the environment.
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Affiliation(s)
- Javier J. How
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California, United States of America
| | - Saket Navlakha
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
- * E-mail: (SN); (SHC)
| | - Sreekanth H. Chalasani
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, San Diego, La Jolla, California, United States of America
- * E-mail: (SN); (SHC)
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34
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Devineni AV, Deere JU, Sun B, Axel R. Individual bitter-sensing neurons in Drosophila exhibit both ON and OFF responses that influence synaptic plasticity. Curr Biol 2021; 31:5533-5546.e7. [PMID: 34731675 DOI: 10.1016/j.cub.2021.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/04/2021] [Accepted: 10/08/2021] [Indexed: 01/07/2023]
Abstract
The brain generates internal representations that translate sensory stimuli into appropriate behavior. In the taste system, different tastes activate distinct populations of sensory neurons. We investigated the temporal properties of taste responses in Drosophila and discovered that different types of taste sensory neurons show striking differences in their response dynamics. Strong responses to stimulus onset (ON responses) and offset (OFF responses) were observed in bitter-sensing neurons in the labellum, whereas bitter neurons in the leg and other classes of labellar taste neurons showed only an ON response. Individual labellar bitter neurons generate both ON and OFF responses through a cell-intrinsic mechanism that requires canonical bitter receptors. A single receptor complex likely generates both ON and OFF responses to a given bitter ligand. These ON and OFF responses in the periphery are propagated to dopaminergic neurons that mediate aversive learning, and the presence of the OFF response impacts synaptic plasticity when bitter is used as a reinforcement cue. These studies reveal previously unknown features of taste responses that impact neural circuit function and may be important for behavior. Moreover, these studies show that OFF responses can dramatically influence timing-based synaptic plasticity, which is thought to underlie associative learning.
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Affiliation(s)
- Anita V Devineni
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA.
| | - Julia U Deere
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | - Bei Sun
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | - Richard Axel
- Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY 10027, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA.
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35
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Rahmani A, Chew YL. Investigating the molecular mechanisms of learning and memory using Caenorhabditis elegans. J Neurochem 2021; 159:417-451. [PMID: 34528252 DOI: 10.1111/jnc.15510] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/15/2021] [Accepted: 09/08/2021] [Indexed: 11/30/2022]
Abstract
Learning is an essential biological process for survival since it facilitates behavioural plasticity in response to environmental changes. This process is mediated by a wide variety of genes, mostly expressed in the nervous system. Many studies have extensively explored the molecular and cellular mechanisms underlying learning and memory. This review will focus on the advances gained through the study of the nematode Caenorhabditis elegans. C. elegans provides an excellent system to study learning because of its genetic tractability, in addition to its invariant, compact nervous system (~300 neurons) that is well-characterised at the structural level. Importantly, despite its compact nature, the nematode nervous system possesses a high level of conservation with mammalian systems. These features allow the study of genes within specific sensory-, inter- and motor neurons, facilitating the interrogation of signalling pathways that mediate learning via defined neural circuits. This review will detail how learning and memory can be studied in C. elegans through behavioural paradigms that target distinct sensory modalities. We will also summarise recent studies describing mechanisms through which key molecular and cellular pathways are proposed to affect associative and non-associative forms of learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
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36
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Bennett MS. Five Breakthroughs: A First Approximation of Brain Evolution From Early Bilaterians to Humans. Front Neuroanat 2021; 15:693346. [PMID: 34489649 PMCID: PMC8418099 DOI: 10.3389/fnana.2021.693346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/13/2021] [Indexed: 11/13/2022] Open
Abstract
Retracing the evolutionary steps by which human brains evolved can offer insights into the underlying mechanisms of human brain function as well as the phylogenetic origin of various features of human behavior. To this end, this article presents a model for interpreting the physical and behavioral modifications throughout major milestones in human brain evolution. This model introduces the concept of a "breakthrough" as a useful tool for interpreting suites of brain modifications and the various adaptive behaviors these modifications enabled. This offers a unique view into the ordered steps by which human brains evolved and suggests several unique hypotheses on the mechanisms of human brain function.
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37
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Chen Y, Ferrell JE. C. elegans colony formation as a condensation phenomenon. Nat Commun 2021; 12:4947. [PMID: 34400648 PMCID: PMC8368178 DOI: 10.1038/s41467-021-25244-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 07/30/2021] [Indexed: 11/15/2022] Open
Abstract
Phase separation at the molecular scale affects many biological processes. The theoretical requirements for phase separation are fairly minimal, and there is growing evidence that analogous phenomena occur at other scales in biology. Here we examine colony formation in the nematode C. elegans as a possible example of phase separation by a population of organisms. The population density of worms determines whether a colony will form in a thresholded fashion, and a simple two-compartment ordinary differential equation model correctly predicts the threshold. Furthermore, small, round colonies sometimes fuse to form larger, round colonies, and a phenomenon akin to Ostwald ripening – a coarsening process seen in many systems that undergo phase separation – also occurs. These findings support the emerging view that the principles of microscopic phase separation can also apply to collective behaviors of living organisms. Phase separation phenomena have emerged as being of critical importance in biology. Here, using colony formation in C. elegans as model, the authors demonstrate that the basic concepts that underpin phase separation at a molecular level also apply to collective phenomena at the level of a population of organisms.
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Affiliation(s)
- Yuping Chen
- Department of Chemical and Systems Biology, Stanford Medicine, Stanford, CA, USA
| | - James E Ferrell
- Department of Chemical and Systems Biology, Stanford Medicine, Stanford, CA, USA. .,Department of Biochemistry, Stanford Medicine, Stanford, CA, USA.
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38
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Bennett MS. What Behavioral Abilities Emerged at Key Milestones in Human Brain Evolution? 13 Hypotheses on the 600-Million-Year Phylogenetic History of Human Intelligence. Front Psychol 2021; 12:685853. [PMID: 34393912 PMCID: PMC8358274 DOI: 10.3389/fpsyg.2021.685853] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/16/2021] [Indexed: 01/24/2023] Open
Abstract
This paper presents 13 hypotheses regarding the specific behavioral abilities that emerged at key milestones during the 600-million-year phylogenetic history from early bilaterians to extant humans. The behavioral, intellectual, and cognitive faculties of humans are complex and varied: we have abilities as diverse as map-based navigation, theory of mind, counterfactual learning, episodic memory, and language. But these faculties, which emerge from the complex human brain, are likely to have evolved from simpler prototypes in the simpler brains of our ancestors. Understanding the order in which behavioral abilities evolved can shed light on how and why our brains evolved. To propose these hypotheses, I review the available data from comparative psychology and evolutionary neuroscience.
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Karin O, Alon U. Temporal fluctuations in chemotaxis gain implement a simulated-tempering strategy for efficient navigation in complex environments. iScience 2021; 24:102796. [PMID: 34345809 PMCID: PMC8319753 DOI: 10.1016/j.isci.2021.102796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/29/2021] [Accepted: 06/24/2021] [Indexed: 12/01/2022] Open
Abstract
Bacterial chemotaxis is a major testing ground for systems biology, including the role of fluctuations and individual variation. Individual bacteria vary in their tumbling frequency and adaptation time. Recently, large cell-cell variation was also discovered in chemotaxis gain, which determines the sensitivity of the tumbling rate to attractant gradients. Variation in gain is puzzling, because low gain impairs chemotactic velocity. Here, we provide a functional explanation for gain variation by establishing a formal analogy between chemotaxis and algorithms for sampling probability distributions. We show that temporal fluctuations in gain implement simulated tempering, which allows sampling of attractant distributions with many local peaks. Periods of high gain allow bacteria to detect and climb gradients quickly, and periods of low gain allow them to move to new peaks. Gain fluctuations thus allow bacteria to thrive in complex environments, and more generally they may play an important functional role for organism navigation.
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Affiliation(s)
- Omer Karin
- Department Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
- Wellcome Trust–Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, UK
| | - Uri Alon
- Department Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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40
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Emmons SW, Yemini E, Zimmer M. Methods for analyzing neuronal structure and activity in Caenorhabditis elegans. Genetics 2021; 218:6303616. [PMID: 34151952 DOI: 10.1093/genetics/iyab072] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/20/2021] [Indexed: 11/12/2022] Open
Abstract
The model research animal Caenorhabditis elegans has unique properties making it particularly advantageous for studies of the nervous system. The nervous system is composed of a stereotyped complement of neurons connected in a consistent manner. Here, we describe methods for studying nervous system structure and function. The transparency of the animal makes it possible to visualize and identify neurons in living animals with fluorescent probes. These methods have been recently enhanced for the efficient use of neuron-specific reporter genes. Because of its simple structure, for a number of years, C. elegans has been at the forefront of connectomic studies defining synaptic connectivity by electron microscopy. This field is burgeoning with new, more powerful techniques, and recommended up-to-date methods are here described that encourage the possibility of new work in C. elegans. Fluorescent probes for single synapses and synaptic connections have allowed verification of the EM reconstructions and for experimental approaches to synapse formation. Advances in microscopy and in fluorescent reporters sensitive to Ca2+ levels have opened the way to observing activity within single neurons across the entire nervous system.
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Affiliation(s)
- Scott W Emmons
- Department of Genetics and Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 1041, USA
| | - Eviatar Yemini
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, NY 10027, USA
| | - Manuel Zimmer
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna 1090, Austria and.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna 1030, Austria
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41
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Findley TM, Wyrick DG, Cramer JL, Brown MA, Holcomb B, Attey R, Yeh D, Monasevitch E, Nouboussi N, Cullen I, Songco JO, King JF, Ahmadian Y, Smear MC. Sniff-synchronized, gradient-guided olfactory search by freely moving mice. eLife 2021; 10:e58523. [PMID: 33942713 PMCID: PMC8169121 DOI: 10.7554/elife.58523] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 04/22/2021] [Indexed: 01/18/2023] Open
Abstract
For many organisms, searching for relevant targets such as food or mates entails active, strategic sampling of the environment. Finding odorous targets may be the most ancient search problem that motile organisms evolved to solve. While chemosensory navigation has been well characterized in microorganisms and invertebrates, spatial olfaction in vertebrates is poorly understood. We have established an olfactory search assay in which freely moving mice navigate noisy concentration gradients of airborne odor. Mice solve this task using concentration gradient cues and do not require stereo olfaction for performance. During task performance, respiration and nose movement are synchronized with tens of milliseconds precision. This synchrony is present during trials and largely absent during inter-trial intervals, suggesting that sniff-synchronized nose movement is a strategic behavioral state rather than simply a constant accompaniment to fast breathing. To reveal the spatiotemporal structure of these active sensing movements, we used machine learning methods to parse motion trajectories into elementary movement motifs. Motifs fall into two clusters, which correspond to investigation and approach states. Investigation motifs lock precisely to sniffing, such that the individual motifs preferentially occur at specific phases of the sniff cycle. The allocentric structure of investigation and approach indicates an advantage to sampling both sides of the sharpest part of the odor gradient, consistent with a serial-sniff strategy for gradient sensing. This work clarifies sensorimotor strategies for mouse olfactory search and guides ongoing work into the underlying neural mechanisms.
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Affiliation(s)
- Teresa M Findley
- Department of Biology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - David G Wyrick
- Department of Biology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Jennifer L Cramer
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Morgan A Brown
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Blake Holcomb
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Robin Attey
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Dorian Yeh
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Eric Monasevitch
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Nelly Nouboussi
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Isabelle Cullen
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Jeremea O Songco
- Department of Biology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Jared F King
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
| | - Yashar Ahmadian
- Department of Biology and Institute of Neuroscience, University of OregonEugeneUnited States
- Computational & Biological Learning Lab, University of CambridgeCambridgeUnited Kingdom
| | - Matthew C Smear
- Department of Psychology and Institute of Neuroscience, University of OregonEugeneUnited States
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42
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Hino T, Hirai S, Ishihara T, Fujiwara M. EGL-4/PKG regulates the role of an interneuron in a chemotaxis circuit of C. elegans through mediating integration of sensory signals. Genes Cells 2021; 26:411-425. [PMID: 33817914 DOI: 10.1111/gtc.12849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 11/30/2022]
Abstract
Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.
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Affiliation(s)
- Takahiro Hino
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Shota Hirai
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Takeshi Ishihara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - Manabi Fujiwara
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
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43
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Ferkey DM, Sengupta P, L’Etoile ND. Chemosensory signal transduction in Caenorhabditis elegans. Genetics 2021; 217:iyab004. [PMID: 33693646 PMCID: PMC8045692 DOI: 10.1093/genetics/iyab004] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Chemosensory neurons translate perception of external chemical cues, including odorants, tastants, and pheromones, into information that drives attraction or avoidance motor programs. In the laboratory, robust behavioral assays, coupled with powerful genetic, molecular and optical tools, have made Caenorhabditis elegans an ideal experimental system in which to dissect the contributions of individual genes and neurons to ethologically relevant chemosensory behaviors. Here, we review current knowledge of the neurons, signal transduction molecules and regulatory mechanisms that underlie the response of C. elegans to chemicals, including pheromones. The majority of identified molecules and pathways share remarkable homology with sensory mechanisms in other organisms. With the development of new tools and technologies, we anticipate that continued study of chemosensory signal transduction and processing in C. elegans will yield additional new insights into the mechanisms by which this animal is able to detect and discriminate among thousands of chemical cues with a limited sensory neuron repertoire.
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Affiliation(s)
- Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Noelle D L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
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44
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Automated Functional Screening for Modulators of Optogenetically Activated Neural Responses in Living Organisms. Methods Mol Biol 2021. [PMID: 32865748 DOI: 10.1007/978-1-0716-0830-2_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
All-optical methods of probing in vivo brain function are advantageous for their compatibility with automated microscopy and fast spatial targeting of neural circuit excitation and response. Recent advances in optogenetic technologies allow simultaneous light activation of specific neurons and optical readout of neural activity via fluorescent calcium reporters, providing an attractive opportunity for high-throughput screening assays that directly assess dynamic neural function in vivo. Here we describe a method to automatically record optogenetically activated neural responses in living, hydrogel-embedded organisms over many hours in a multiwell plate format. This method is suitable for screening the neural effects of hundreds of chemical compounds and assessing the time course of bioactivity over 12 h or more. As examples, we show the suppression of neural responses over time with various concentrations of two voltage-gated calcium channel blockers and a full-plate screen of 320 chemicals with positive and negative controls in a single experiment.
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45
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Rabinowitch I, Upadhyaya B, Pant A, Galski D, Kreines L, Bai J. Circumventing neural damage in a C. elegans chemosensory circuit using genetically engineered synapses. Cell Syst 2021; 12:263-271.e4. [PMID: 33472027 PMCID: PMC7979504 DOI: 10.1016/j.cels.2020.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/03/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
Neuronal loss can considerably diminish neural circuit function, impairing normal behavior by disrupting information flow in the circuit. Here, we use genetically engineered electrical synapses to reroute the flow of information in a C. elegans damaged chemosensory circuit in order to restore organism behavior. We impaired chemotaxis by removing one pair of interneurons from the circuit then artificially coupled two other adjacent neuron pairs by ectopically expressing the gap junction protein, connexin, in them. This restored chemotaxis in the animals. We expected to observe linear and direct information flow between the connexin-coupled neurons in the recovered circuit but also revealed the formation of new potent left-right lateral electrical connections within the connexin-expressing neuron pairs. Our analysis suggests that these additional electrical synapses help restore circuit function by amplifying weakened neuronal signals in the damaged circuit in addition to emulating the wild-type circuit. A record of this paper's transparent peer review process is included in the Supplemental Information.
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Affiliation(s)
- Ithai Rabinowitch
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel.
| | - Bishal Upadhyaya
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Aaradhya Pant
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Dolev Galski
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Lena Kreines
- Department of Medical Neurobiology, IMRIC - Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112002, Israel
| | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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46
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Neural and behavioral control in Caenorhabditis elegans by a yellow-light-activatable caged compound. Proc Natl Acad Sci U S A 2021; 118:2009634118. [PMID: 33542099 DOI: 10.1073/pnas.2009634118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Caenorhabditis elegans is used as a model system to understand the neural basis of behavior, but application of caged compounds to manipulate and monitor the neural activity is hampered by the innate photophobic response of the nematode to short-wavelength light or by the low temporal resolution of photocontrol. Here, we develop boron dipyrromethene (BODIPY)-derived caged compounds that release bioactive phenol derivatives upon illumination in the yellow wavelength range. We show that activation of the transient receptor potential vanilloid 1 (TRPV1) cation channel by spatially targeted optical uncaging of the TRPV1 agonist N-vanillylnonanamide at 580 nm modulates neural activity. Further, neuronal activation by illumination-induced uncaging enables optical control of the behavior of freely moving C. elegans without inducing a photophobic response and without crosstalk between uncaging and simultaneous fluorescence monitoring of neural activity.
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47
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Sleep Analysis in Adult C. elegans Reveals State-Dependent Alteration of Neural and Behavioral Responses. J Neurosci 2021; 41:1892-1907. [PMID: 33446520 PMCID: PMC7939084 DOI: 10.1523/jneurosci.1701-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 01/26/2023] Open
Abstract
Sleep, a state of quiescence associated with growth and restorative processes, is conserved across species. Invertebrates including the nematode Caenorhabditis elegans exhibit sleep-like states during development, satiety, and stress. Here, we describe behavior and neural activity during sleep and awake states in adult C. elegans hermaphrodites using new microfluidic methods. We observed effects of fluid flow, oxygen, feeding, odors, and genetic perturbations on long-term sleep behavior over 12 h. We developed a closed-loop sleep detection system to automatically deliver chemical stimuli to assess sleep-dependent changes to evoked neural responses in individual animals. Sleep increased the arousal threshold to aversive stimulation, yet the associated sensory neuron and first-layer interneuron responses were unchanged. This localizes adult sleep-dependent neuromodulation within interneurons presynaptic to the premotor interneurons, rather than afferent sensory circuits. However, sleep prolonged responses in appetitive chemosensory neurons, suggesting that sleep modulates responsiveness specifically across sensory systems rather than broadly damping global circuit activity. SIGNIFICANCE STATEMENT Much is known about molecular mechanisms that facilitate sleep control. However, it is unclear how these pathways modulate neural circuit-level sensory processing or how misregulation of neural activity contributes to sleep disorders. The nematode Caenorhabditis elegans provides the ability to study neural circuitry with single-neuron resolution, and recent studies examined sleep states between developmental stages and when stressed. Here, we examine an additional form of spontaneous sleep in adult C. elegans at the behavioral and neural activity levels. Using a closed-loop system, we show that delayed behavioral responses to aversive chemical stimulation during sleep arise from sleep-dependent sensorimotor modulation localized presynaptic to the premotor circuit, rather than early sensory circuits.
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Fadda M, De Fruyt N, Borghgraef C, Watteyne J, Peymen K, Vandewyer E, Naranjo Galindo FJ, Kieswetter A, Mirabeau O, Chew YL, Beets I, Schoofs L. NPY/NPF-Related Neuropeptide FLP-34 Signals from Serotonergic Neurons to Modulate Aversive Olfactory Learning in Caenorhabditis elegans. J Neurosci 2020; 40:6018-6034. [PMID: 32576621 PMCID: PMC7392509 DOI: 10.1523/jneurosci.2674-19.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 04/26/2020] [Accepted: 06/12/2020] [Indexed: 02/03/2023] Open
Abstract
Aversive learning is fundamental for animals to increase chances of survival. In addition to classical neurotransmitters, neuropeptides have emerged to modulate such complex behaviors. Among them, neuropeptide Y (NPY) is well known to promote aversive memory acquisition in mammals. Here we identify an NPY/neuropeptide F (NPF)-related neuropeptide system in Caenorhabditis elegans and show that this FLP-34/NPR-11 system is required for learning negative associations, a process that is reminiscent of NPY signaling in mammals. The Caenorhabditis elegans NPY/NPF ortholog FLP-34 displays conserved structural hallmarks of bilaterian-wide NPY/NPF neuropeptides. We show that it is required for aversive olfactory learning after pairing diacetyl with the absence of food, but not for appetitive olfactory learning in response to butanone. To mediate diacetyl learning and thus integrate the aversive food context with the diacetyl odor, FLP-34 is released from serotonergic neurons and signals through its evolutionarily conserved NPY/NPF GPCR, NPR-11, in downstream AIA interneurons. NPR-11 activation in the AIA integration center results in avoidance of a previously attractive stimulus. This study opens perspectives for a deeper understanding of stress conditions in which aversive learning results in excessive avoidance.SIGNIFICANCE STATEMENT Aversive learning evolved early in evolution to promote avoidance of dangerous and stressful situations. In addition to classical neurotransmitters, neuropeptides are emerging as modulators of complex behaviors, including learning and memory. Here, we identified the evolutionary ortholog of neuropeptide Y/neuropeptide F in the nematode Caenorhabditis elegans, and we discovered that it is required for olfactory aversive learning. In addition, we elucidated the neural circuit underlying this avoidance behavior, and we discovered a novel coordinated action of Caenorhabditis elegans neuropeptide Y/neuropeptide F and serotonin that could aid in our understanding of the molecular mechanisms underlying stress disorders in which excessive avoidance results in maladaptive behaviors.
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Affiliation(s)
- Melissa Fadda
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | | | | | - Olivier Mirabeau
- Genetics and Biology of Cancers Unit, Institut Curie, Institut National de la Santé et de la Recherche Médicale U830, Paris Sciences et Lettres Research University, Paris, 75005, France
| | - Yee Lian Chew
- Illawarra Health & Medical Research Institute School of Chemistry & Molecular Bioscience, University of Wollongong, Wollongong, 2522 New South Wales, Australia
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
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Gonzales DL, Badhiwala KN, Avants BW, Robinson JT. Bioelectronics for Millimeter-Sized Model Organisms. iScience 2020; 23:100917. [PMID: 32114383 PMCID: PMC7049667 DOI: 10.1016/j.isci.2020.100917] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/29/2020] [Accepted: 02/10/2020] [Indexed: 01/27/2023] Open
Abstract
Advances in microfabrication technologies and biomaterials have enabled a growing class of electronic devices that can stimulate and record bioelectronic signals. Many of these devices have been developed for humans or vertebrate animals, where miniaturization allows for implantation within the body. There are, however, another class of bioelectronic interfaces that exploit microfabrication and nanoelectronics to record signals from tiny, millimeter-sized organisms. In these cases, rather than implanting a device inside an animal, animals themselves are loaded in large numbers into bioelectronic devices for neural circuit and behavioral interrogation. These scalable interfaces provide platforms to develop new therapeutics as well as better understand basic principles of bioelectronic communication, neuroscience, and behavior. Here we review recent progress in these bioelectronic technologies and describe how they can complement on-chip optical, mechanical, and chemical interrogation methods to achieve high-throughput, multimodal studies of millimeter-sized small animals.
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Affiliation(s)
- Daniel L Gonzales
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA
| | - Krishna N Badhiwala
- Department of Bioengineering, Rice University, 6100 Main St., Houston, TX 77005, USA
| | - Benjamin W Avants
- Department of Electrical and Computer Engineering, Rice University, 6100 Main St., Houston, TX 77005, USA
| | - Jacob T Robinson
- Department of Bioengineering, Rice University, 6100 Main St., Houston, TX 77005, USA; Department of Electrical and Computer Engineering, Rice University, 6100 Main St., Houston, TX 77005, USA; Applied Physics Program, Rice University, 6100 Main St., Houston, TX 77005, USA; Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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50
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Shimizu K, Ashida K, Hotta K, Oka K. Food deprivation changes chemotaxis behavior in Caenorhabditis elegans. Biophys Physicobiol 2020; 16:167-172. [PMID: 31984168 PMCID: PMC6975978 DOI: 10.2142/biophysico.16.0_167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/19/2019] [Indexed: 12/01/2022] Open
Abstract
Exploring for food is important in food-deprived condition. Chemotaxis is one of the important behaviors to search food. Although chemotactic strategies in C. elegans have been well investigated: the pirouette and the weathervane strategies, the change of the chemotactic strategy by food deprivation is largely unclear. Here, we show the change of chemotactic strategy by food deprivation, especially for isoamyl alcohol. To compare chemotaxis under different food-deprivation period, we showed that worms change their chemotactic behaviors by food deprivation. The worms with 1-h food-deprivation change the weathervane strategy. On the other hand, 6-h food deprived animals change the pirouette strategy. These results demonstrate that worms change chemotactic strategy different way depend on period of food deprivation.
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Affiliation(s)
- Kei Shimizu
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Keita Ashida
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan.,Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan
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